Class 12 Chemistry MCQ Questions of Surface Chemistry with Answers is available for college students preparing to the newest syllabus guidelines. Solve MCQ Questions for class 12 to boost your speed and accuracy within the actual board exams. We have provided Surface Class 12 MCQ Questions with Answers to assist students understands the concept alright.

Surface chemistry deals with the study of the phenomena occurring at the surface of the boundary separating two bulk phases. Adsorption is that the process of attracting and holding a substance’s molecules on the surface of a liquid or a solid leading to a better surface concentration of the molecules.

Check the below MCQ Question for class 12 Chemistry Surface Chemistry with Answers. MCQ Questions for class 12 Chemistry with Answers were prepared based on the newest exam pattern. 

Practice MCQ Question for Class 12 Chemistry chapter-wise

1. Tyndall effect confirms the

(a) gravity effect on the sol. particles
(b) light scattering by the sol. particles
(c) heterogeneous nature of sols
(d) Brownian motion of the sol. particles

2. Which one of the following is a lyophilic colloid?

(a) Milk
(b) Gum
(c) Fog
(d) Blood

3. Shape selective catalysis is a reaction catalysed by

(a) zeolite
(b) enzymes
(c) platinum
(d) Ziegler-Natta catalyst

4. Which of the following types of metals make the most efficient catalyst?

(a) Alkali metals
(b) Transition metals
(c) Inner transition metals
(d) Alkaline earth metals

5. The oxide of nitrogen which acts as a catalyst in lead chamber process is

(a) NO
(b) NO₂
(c) N₂O₄
(d) H₂O₅

6. The activity of an enzyme becomes ineffective

(a) at low temperature
(b) at atmospheric pressure
(c) at high temperature
(d) in aqueous medium

7. Which of the following can adsorb larger volume of hydrogen gas?

(a) Finely divided platinum
(b) Colloidal solution of palladium
(c) Small pieces of palladium
(d) A single metal surface of platinum

8. Which of the following gases present in a polluted area will be adsorbed most easily on the charcoal gas mask?

(a) H₂
(b) O₃
(c) N₂
(d) SO₂

9. Which kind of catalysis can be explained on the basis of adsorption theory?

(a) Homogeneous catalysis
(b) Heterogeneous catalysis
(c) Negative catalysis
(d) Auto catalysis

10. A colloidal system is which liquid is dispersed phase and solid is dispersion medium is classified as

(a) gel
(b) sol
(c) emulsion
(d) aerosol

11. Substances which behave as normal electrolytes solution at low concentration and exhibit colloids properties at higher concentration are called

(a) lyophilic colloids
(b) lyophobic colloids
(c) macromolecular colloids
(d) associated colloids

12. The formation of micelles takes place only above

(a) critical temperature
(b) Kraft temperature
(c) inversion temperature
(d) absolute temperature

13. Why is alum added to water containing suspended impurities?

(a) To make a colloidal solution
(b) To coagulate the suspended impurities
(c) To remove impurities of calcium and magnesium
(d) To protect the colloidal solution from gening precipitated

14. Movement of dispersion medium under the influence of electric field is known as

(a) electrodialysis
(b) electrophoresis
(c) electroosmosis
(d) cataphoresis

15. The physical adsorption of gases on the solid surface is due to:

(a) Covalent bond
(b) Hydrogen bond
(c) Ionic bond
(d) Van der waal's forces

16. The electrical charge on a colloidal particle is observed by:

(a) Ultramicroscope
(b) Scattering
(c) Brownian movement
(d) Electrophoresis

17. Purple of cassius is colloidal solution of :

(a) Silver
(b) Lead
(c) Gold
(d) Mercury

18. Milk is colloid in which :

(a) Liquid is dispersed in liquid
(b) Gas is dispersed in liquid
(c) Sugar is dispersed in water
(d) Solid is dispersed in liquid

19. Which of the following is a lyophobic colloidal solution?

(a) Aqueous starch solution
(b) Aqueous protein solution
(c) Gold solution
(d) Polymer solvent in some organic solvents

20. Butter is a colloid form in which:

(a) fat is dispersed in solid casein
(b) fat globules are dispersed in water
(c) water is dispersed in fat
(d) suspension of casein is in water

21. Negative catalyst or inhibitor is one:

(a) which retards the rate of reaction
(b) takes the reaction in forward direction
(c) promotes the side reaction
(d) none of the above

22. Alum helps in purifying water by:

(a) Forming Si complex with clay particles
(b) Sulphate part which combines with the dirt and removes it
(c) Aluminium which coagulates the mud particles
(d) Making mud water soluble

23. Milk can be preserved by adding a few drops of:

(a) Formic acid solution             
(b) Formaldehyde solution
(c) Acetic acid solution             
(d) Acetaldehyde solution

24. Clouds, mist, fog and aerosols are colloidal solution of:

(a) solid in a gas
(b) gas in a solid
(c) liquid in a gas
(d) gas in a liquid

25. Gold number is the index for:

(a) Protective power of lyophilic colloid
(b) Purity of gold
(c) Metallic gold
(d) Electroplated gold

Answer :

1. Answer : (c) heterogeneous nature of sols

Explanation: Tyndall effect confirms the heterogeneous nature of the colloidal solution.it is observed due to the scattering of dust particles. Tyndall effect is used to distinguish between the true solution and the colloidal solution.

2. Answer : (b) Gum

Explanation: In such solids, the dispersed phase does not easily precipitate and the sols are quite stable. These sols are reversible in nature.If water is used as the dispersion medium, lyophilic sols are called hydrophilic sols. Starch, gum, gelatin, egg albumin etc.

3. Answer : (a) zeolite

Explanation: The shape-selective catalysis is a reaction catalysed by Zeolites. Because the structure of Zeolites is like a honeycomb. Hence it is used as the catalyst in the chemical reaction. Zeolites are especially used as Shape-selective catalysis.

4. Answer : (b) Transition metals

Explanation: The transition metals are considered to make the most efficient catalysts. This is because, when these metals are with suitable reactants, they form unstable intermediate products that can lower the activation energy and thereby making the reaction faster.

5. Answer : (a) NO

Explanation: The process of producing sulfuric acid by oxidizing sulfur dioxide with moist air, using gaseous nitrogen oxides as catalysts, is known as Lead chamber process. This reaction takes place primarily in a series of large, boxlike chambers of sheet lead.

6. Answer : (c) at high temperature

Explanation: Enzymes are effective only at optimum temperature. They become ineffective at very high temperature.

7. Answer : (b) Colloidal solution of palladium

Explanation: An excellent absorbed hydrogen gas is palladium. Therefore, colloidal solutions of palladium could adsorb greater volume of hydrogen gas as the surface area of palladium is the most colloidal solution of palladium.

8. Answer : (d) SO₂

Explanation: The amount of gas adsorbed by a solid depends on the nature of gas. In general, easily liquefiable gases. Easily liquefiable gases will have higher critical temperatures are readily adsorbed as van der Waals’ forces are stronger near the critical temperatures.SO₂ is having the maximum critical temperature and hence it gets adsorbed most easily on the charcoal gas mask.

9. Answer : (b) Heterogeneous catalysis

Explanation: Adsorption theory of Heterogeneous catalyst is adsorption theory of catalysis, the reactions in their gaseous state on in their dissolved state in any solution gets adsorbed on the surface of
a suitable catalyst in its solid state.

10. Answer : (a) gel

Explanation: A colloidal system in which liquid is a dispersed phase and solid is dispersion medium is known as Gel. Example-Cheese, jellies.

11. Answer : (d) associated colloids

Explanation: Associated colloids are substances which at low concentrations behave as normal strong electrolytes, but at higher concentrations exhibit colloidal behaviour due to the formation of aggregates.
The aggregated particles formed are called micelles. The formation of micelles takes place only above a particular temperature called Kraft temperature and above a particular concentration called critical micelle concentration.

12. Answer : (b) Kraft temperature

Explanation: The formation of micelles takes place only above a particular temperature called Kraft temperature (TK).

13. Answer : (b) To coagulate the suspended impurities

Explanation: When alum is added to raw water it reacts with the bicarbonates alkalinities present in water and forms a gelatinous precipitate. It neutralizes all the suspended impurities of water resulting in their coagulation.

14. Answer : (c) electroosmosis

Explanation: When movement of particles (electrophoresis) is prevented by some suitable means, it is observed that the dispersion medium begins to move in an electric field. This phenomenon is termed as electroosmosis.

15. Answer : (d) Van der waal's forces

Explanation: When the force of attraction existing between adsorbate and adsorbent are weak Vanderwaal forces of attraction, the process is called Physical Adsorption or Physisorption. When the force of attraction existing between adsorbate and adsorbent are chemical forces of attraction or chemical bond, the process is called Chemical Adsorption.

16. Answer : (d) Electrophoresis

Explanation: Colloidal particles possess some type of electric charge. The migration of colloidal particles under the influence of an electric field is known as electrophoresis.

17. Answer : (c) Gold

Explanation: Gold is dissolved in the aqua medium and it further reduces to give a purple precipitate. Therefore, purple of cassius is a colloidal sol of gold.

18. Answer : (a) Liquid is dispersed in liquid

Explanation: Milk is an emulsified colloid of Liquid is dispersed in liquid where liquid butterfat globules dispersed within a water-based solution. 

19. Answer : (c) Gold solution

Explanation: Gold sol is a lyophobic sol. Gold particles have very less affinity towards dispersion medium, hence its sol can be easily coagulated.

20. Answer : (c) water is dispersed in fat

Explanation: A colloid is a mixture where a particular substance is trapped in a given dispersion medium but do not get mixed chemically. Butter is a colloidal formed when water is dispersed in fat.

21. Answer : (a) which retards the rate of reaction

Explanation: The catalyst which decreases the rate of reaction is known as inhibitor or negative catalyst and the process is known as negative catalysis or inhibition. Negative catalysts are useful to slow down or stop any unwanted reactions.

22. Answer : (c) Aluminium which coagulates the mud particles

Explanation: Alum is added to water in order to destabilize the mud particles suspended in it. This process is known as coagulation. Alum helps in purifying water by aluminium which helps to coagulate the mud particles.

23. Answer : (b) Formaldehyde solution

Explanation: Formaldehyde solution is an emulsifier which is added in the milk as it acts as a preserving agent for the milk.

24. Answer : (c) liquid in a gas

Explanation: Fog or cloud is a colloidal dispersion of water droplets in a dispersion medium of gas. When the dispersion medium is gas, the dispersed phase can be solid or liquid but not gas.

25. Answer : (a) Protective power of lyophilic colloid

Explanation: The Gold Number is the minimum weight (in milligrams) of a protective colloid required to prevent the coagulation of 10 ml of a standard hydro gold sol when 1 ml of a 10% sodium chloride solution is added to it.

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